A radiotherapy system with real-time magnetic resonance monitoring is known from WO2009/156896 A1. The described system allows for real-time monitoring for radiation.
The described system compares real-time monitoring images with a reference image during radiotherapy by using an image comparator to identify any changes in the subject since the radiotherapy planning stage. This information may be used for repositioning of the subject or for updating the radiotherapy plan. The updated radiotherapy plan adjusts the subsequently applied radiation pulses to adapt the radiotherapy plan to accommodate the identified subject motion.
US2013035588 describes methods, systems and computer readable media for therapy planning using magnetic resonance imaging. The motion or position of the treatment region is tracked over time for many cycles using MRI. The tracking is used to compare with the surrogate motion or signal to establish the long term surrogate-to-tumor correspondence. The motion of the object is compared to the surrogate motion (determined by measurements of the motion or position of tissue (e.g. skin or chest) or using navigation images). The comparison is used to determine whether the position variation of the object in the cycle results in inaccuracies in the gated treatment. Furthermore, US2013035588 describes that a determined position is used for therapy planning. The position is used for planning using tumoral spatial probability density functions.